Holocarboxylase Synthetase Deficiency, also known as early-onset multiple carboxylase deficiency, is related to multiple carboxylase deficiency and metabolic acidosis, and has symptoms including exanthema, lethargy and seizures. An important gene associated with Holocarboxylase Synthetase Deficiency is HLCS (Holocarboxylase Synthetase), and among its related pathways/superpathways are Metabolism and Metabolism of water-soluble vitamins and cofactors. Affiliated tissues include skin and liver, and related phenotypes are seizure and nausea and vomiting